Prepare the Batter:

• In a mixing bowl, beat the eggs and granulated sugar with an electric mixer on high speed for about 3–4 minutes, until the mixture is pale, thick, and fluffy.
• Mix in the vanilla extract and lemon zest (if using).

Sift and Fold Dry Ingredients:

• In a separate bowl, whisk together the flour, baking powder, and salt.
• Gently fold the dry ingredients into the egg mixture using a spatula until just combined.

Add the Butter and Cream:

• Drizzle in the melted butter and heavy cream, folding gently until fully incorporated.

Chill the Batter:

• Cover the bowl and refrigerate for at least 1 hour (or up to overnight). This step helps create the signature madeleine “hump.”

Prepare the Madeleine Pan:

• Preheat your oven to 375°F (190°C).
• Grease a madeleine pan with butter and a light dusting of flour, or use non-stick spray.

Bake:

• Spoon about 1 tablespoon of batter into each madeleine mold. Don’t spread it out; it will naturally fill the shape as it bakes.
• Bake for 10–12 minutes, until the edges are golden brown and the tops spring back when lightly touched.

Cool and Serve:

• Let the madeleines cool in the pan for a few minutes, then transfer them to a wire rack.
• Dust with powdered sugar before serving.